Null cell immunoregulation in SLE.

Fresh normal T cells do not lyse MDA-157 target cells. Normal null cells, cultured for 4 days with MDA-157 stimulators, and then mixed overnight with fresh normal T cells, induce cytotoxicity on MDA-157 targets and suppressor activity in the T-cell acceptor population. With the same normal acceptor T cells, MDA-157 activated null cells from 13/18 patients with Systemic Lupus Erythematosus (SLE), unlike activated cells from a disease control population, induce little or no T-cell cytotoxicity or suppression. These results provide further evidence for abnormal null cell function in SLE.